This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. It is accepted that male and females from many different species store fat differently, with males having a greater storage of adipose tissue in visceral stores and females having greater subcutaneous stores. It is also accepted that visceral fat levels are linked increased cardiovascular risk as well as other metabolic diseases. Consistent with the higher levels of visceral fat, men have a higher risk of cardiovascular disease. In spite of these accepted differences in fat storage and the differential risk factors, little is known about the functional differences between the two types of adipose tissues. Furthermore, there is little known about the effects of gonadal steroids on adipose tissue function. For this study we are performing an Affymetrix microarray analysis to profile differences in gene expression in different subcutaneous and visceral white adipose tissue pads in male, female mice. The male, female (at proestrus when estrogen levels are high) and ovariectomized female mice for this study are on a high fat diet for 16 weeks, at which time all three groups are obese and insulin resistant. Animals are sacrificed and gonadal (visceral) and inguinal (subcutaneous) fat pads are isolated and mRNA extracted. Gene expression profiles are being generated Affymetrix chips and differential gene expression confirmed by quantitative PCR. These studies will provide critical insight into the differential regulation of visceral and subcutaneous fat pads in males and females as well as the effect of gonadal hormones.